the light-hours is a debate that will probably always be disputed ... I have used the 18/6 veg 12/12 flower schedule successfully for a long, long time, have tried other schedules, but always go back ...
here is a very interesting article, by DJ Shorts, the famous breeder ... mid-way down, he starts discussing different light schedules, to bring out desired characteristics (imitating lighting schedules of the landrace origins) ... thought-provoking Breeding tips | Cannabis Culture Magazine :thumbsup: